Fetal tachyarrhythmia with atrial flutter in obstetric cholestasis

Obstetric cholestasis is a liver disease occurring in the third trimester of pregnancy and characterized by generalized pruritus, with possible elevated plasma bile acids and other liver enzymes. It is associated with intrauterine death, fetal distress, and preterm labor [1]. Most reported cases of fetal distress are tachycardias, bradycardias, bradydysrrhythmias, and late decelerations with loss of variability [1]. Fetal tachydysrrhythmia leading to atrial flutter has not previously been reported in conjunction with obstetric cholestasis. A 19-year-old primigravida with uneventful antenatal history was diagnosed with obstetric cholestasis at 37 weeks' gestation. She had generalized pruritis, with a high serum bile acid. Fetal well being and cardiac scan were normal and cardiotocography (CTG) was reactive. Induction of labor was commenced. Fetal tachydysrrhythmia leading to atrial flutter developed in labor (Fig. 1). The fetal heart rate ranged between 220 and 230 beats per minute (bpm) (audible but not recorded on the CTG trace with a baseline of 140 bpm in-between). This was followed by atrial flutter, confirmed by ultrasound scan (regular atrial wall motion of 400 bpm at a rate of 4: 1 to ventricular wall motion). Cervix was dilated to 3 cm. A live male infant weighing 3600 g was delivered by immediate cesarean section. His heart rate returned to normal immediately postpartum. Cord blood gases were normal. The infant's echocardiography and electrocardiography were normal. Both mother and infant did well postoperatively. The CTG showing a base line of 140 bpm withd fetal tachydysrrhythmia in between (fetal heart rate audible at 220–240 bpm). Although it has been postulated that bile acids induce contractions within chorionic vessels, resulting in reduction of feto-placental blood flow causing acute fetal asphyxia and death [1], several authors do not support this postulation [1], [2]. A possible mechanism of sudden intrauterine fetal death, which may be preceded by fetal heart abnormality, was demonstrated in an in vitro study. It showed impairment of fetal cardiomyocyte function by the raised levels of the bile acid taurocholate causing dysrrhythmia, cardiac arrest and sudden cardiac death [2]. Sudden cardiac death can be attributed to tachyarrhythmias, although asystole, ventricular fibrillation and severe bradycardia can also be distinct possibilities [2]. However, not all cases of fetal death in obstetric cholestasis are preceded by cardiac dysfunction. The normal cord blood pH values in this case do not refer to the probability of a previous intrauterine hypoxia as a cause of the pathology. The infant had normal postnatal cardiac examination. Bile acid could be the leading cause of fetal tachydysrrhythmia and atrial flutter.